import os, shutil
src_folder = 'C:/maishu/images'  
big_folder = os.path.join('C:/maishu', 'big_images')

if not os.path.exists(big_folder):
    os.makedirs(big_folder)

for dirname, subdirlist, filelist in os.walk(src_folder):
    for file in filelist:
        file_path = os.path.join(dirname, file)
        size_in_kb = os.path.getsize(file_path)/1024
        if file.endswith(('.jpg', '.jpeg', '.png', '.gif')) and size_in_kb > 30:
            shutil.copy2(file_path, big_folder)


